Wireless transmission systems that make use of basestation antennas are configured according to the customer and network requirements. In particular, fixed broadband wireless networks which operate within a range of frequencies on different frequency bands can make use of several different types of antennas to enable the transmission and reception of the radio signals between various sites. Although a fixed wireless system may operate on as few as three different frequency bands, a system which may need to operate on a few different polarization scheme may require as many as 60 different antennas.
The problem associated with previous antenna designs is that if a different radiation pattern is required, a new antenna would have to be selected to provide this radiation pattern. Since multiple radiation patterns may be required in a multiband wireless network, several different types of antennas will be required thereby increasing the infrastructure cost of the network. In addition, once the antenna is installed in the field, there is very little flexibility which permit the modification of the radiation pattern without having to change the entire antenna.
For example, within each frequency band an antenna operating within say, a 90, 60, 45, 30 and 15 degree sector may be required. Since the system may require horizontally and vertically polarized antennas, many different styles of antennas are required.
A need therefore exists for a modular antenna which can overcome the problems associated with the prior art antennas. In particular, a need exists for an antenna arrangement which can be modified to change the beamwidth capability of the antenna without having to change the physical antenna aperture portion of the antenna.